MCI Progress to Dementia: Estimates, Role of Depression

(HealthDay News) — About 22% of patients with mild cognitive impairment (MCI) progress to dementia within three years, and depression symptoms modify the prognosis, according to a study published in the March/April issue of the Annals of Family Medicine.

Hanna Kaduszkiewicz, MD, from the Center for Psychosocial Medicine in Hamburg, Germany, and colleagues recruited 357 patients with MCI aged ≥75 years and followed them for three years. The patients were retrospectively categorized according to the course of impairment over time into remittent, fluctuating, stable, and progressive courses of MCI.

The researchers found that 41.5% of patients had symptom remission with normal cognitive function at 1.5 and three years; 21.3, 14.8, and 22.4% had a fluctuating course, stable symptoms, and progression to dementia. The risk of advancing from one course to the next was increased for patients with symptoms of depression, impairment in more than one cognitive domain, or more severe cognitive impairment, and for older patients. The best indicator for differentiating between remittent and progressive MCI was the result on a test of the ability to learn and reproduce new material 10 minutes later. The prognosis was modified by depression.

"In primary care, about one-quarter of patients with MCI have progression to dementia within the next three years," the authors write "When transferring the concept of MCI into clinical diagnostic algorithms (e.g., Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition), however, we should not forget that three-quarters of patients with MCI stayed cognitively stable or even improved within three years. They should not be alarmed unnecessarily by receiving such a diagnosis."